177
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Deutsch
Documents
2008
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177
pages
Deutsch
Documents
2008
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Star-shaped Polyelectrolytes
DISSERTATION
zur Erlangung des akademischen Grades eines
Doktors der Naturwissenschaften (Dr. rer. nat.)
im Fach Chemie der Fakultät für Biologie, Chemie und Geowissenschaften
der Universität Bayreuth
Vorgelegt von
Felix Plamper
Geboren in Weiden i. d. Opf.,
Bayreuth, 2007
Die vorliegende Arbeit wurde in der Zeit von Februar 2004 bis Juli 2007 in Bayreuth am
Lehrstuhl Makromolekulare Chemie II unter Betreuung von Herrn Prof. Dr. Axel H. E.
Müller angefertigt.
Prüfungsausschuss:
Prof. Dr. Helmut Alt
Prof. Dr. Matthias Ballauff (Zweitgutachter)
Prof. Dr. Alexander Böker (Vorsitzender)
Prof. Dr. Axel H. E. Müller (Erstgutachter)
Tag der Einreichung: 13. Juli 2007
Tag des wissenschaftliches Kolloquiums: 20. Dezember 2007
Amtierender Dekan: Prof. Dr. Axel H. E. Müller
Vollständiger Abdruck der von der Fakultät für Biologie, Chemie und Geowissenschaften der
Universität Bayreuth genehmigten Dissertation zur Erlangung des Grades eines Doktor der
Naturwissenschaften (Dr. rer. nat.).
And when they saw the star,
they rejoiced exceedingly with great joy.
Bible, Mt 2.10
dedicated to my family
Table of Contents
Table of Contents
1. Introduction .......................................................................................................................... 1
1.1. Star-shaped Polymers ................................................................................................... 1
1.1.1. Classification and Properties ................................................................................. 1
1.1.2. Synthesis of Star-Shaped Polymers ...................................................................... 3
1.2. Polyelectrolytes – Introduction .................................................................................... 8
1.2.1. Classification ........................................................................................................... 8
1.2.2. Theory of Linear Polyelectrolytes ......................................................................... 9
1.2.3. Theory of Star-Shaped Polyelectrolytes ............................................................. 12
1.3. Phase Separation in Polymer Solutions ..................................................................... 17
1.4. Experimental Methods of Determining the Solution Behavior of Star-shaped
Polyelectrolytes ................................................................................................................... 20
1.4.1. Potentiometric Titration ...................................................................................... 20
1.4.2. Osmotic Pressure and Osmotic Coefficient ....................................................... 21
1.4.3. Dynamic Light Scattering .................................................................................... 23
1.4.4. Common Techniques for the Determination of Molecular Weight ................. 25
1.5. Objective of this Thesis ............................................................................................... 30
1.6. References .................................................................................................................... 31
2. Overview of thesis – Results .............................................................................................. 36
2.1. Synthesis of Star-Shaped Polyelectrolytes ................................................................ 37
2.2. Titration Behavior of Star-Shaped Weak Polyelectrolytes ..................................... 38
2.3. Counterion Distribution of Star-Shaped Polyelectrolytes ....................................... 40
2.4. Conformational Changes in Polycation Stars Induced by the Presence of Salt and
the Use of Light-Sensitive Salt ........................................................................................... 41
2.5. Temperature-Induced Phase Separation in Solutions of Star-Shaped and Linear
PDMAEMA ......................................................................................................................... 44
2.6. Individual Contributions to Joint Publications ........................................................ 45
2.7. References .................................................................................................................... 47
3. Synthesis, Characterization and Aqueous Solution Behaviour of Star-shaped
Poly(acrylic acid)49
3.1. Introduction ................................................................................................................. 50
3.2. Experimental Part ....................................................................................................... 51
3.3. Results and Discussion ................................................................................................ 57
3.3.1. Synthesis and Characterization of Oligoinitiators ............................................ 57
3.3.2. Synthesis and Characterization of Poly(acrylic acid) stars .............................. 59
3.3.3. Potentiometric Titration ...................................................................................... 66
3.3.4. Osmometry – Determination of Osmotic Coefficient ........................................ 67
Table of Contents
3.4. Conclusion .................................................................................................................... 69
3.5. References70
4. Synthesis and Characterization of Star-Shaped Poly(N,N-dimethylaminoethyl
methacrylate) and Its Quaternized Ammonium Salts ........................................................ 73
4.1. Introduction ................................................................................................................. 74
4.2. Experimental Section .................................................................................................. 76
4.3. Results and Discussion ................................................................................................ 80
4.3.1 Synthesis of Star-Shaped Poly(N,N-dimethylaminoethyl methacrylate) ......... 80
4.3.2. Quaternization of PDMAEMA Stars ................................................................. 84
4.3.3. Determination of Initiation Site Efficiency ........................................................ 84
4.3.4. Hydrodynamic Behavior ...................................................................................... 88
4.3.5. Cryogenic Transmission Electron Microscopy .................................................. 90
4.3.6. Osmotic Coefficients ............................................................................................ 91
4.4. Conclusions .................................................................................................................. 92
4.5. Supporting Information .............................................................................................. 93
4.6. References100
5. Nanoblossoms: Light-Induced Conformational Changes of Cationic Polyelectrolyte
Stars in Presence of Multivalent Counterions ................................................................... 103
5.1. Introduction ............................................................................................................... 104
5.2. Experimental Section ................................................................................................ 105
5.3. Results and Discussion107
5.3.1. Collapse of Polyelectrolyte Stars Induced by Multivalent Counterions ....... 107
5.3.2. Photostretching of Polyelectrolyte Stars .......................................................... 110
5.3.3. Photodissolution of Polyelectrolyte Stars ......................................................... 111
5.4. Conclusion .................................................................................................................. 112
5.5. References113
6. Tuning the Thermoresponsive Properties of Weak Polyelectrolytes: Aqueous
Solutions of Star-Shaped and Linear Poly(N,N-dimethylaminoethyl methacrylate) .... 114
6.1. Introduction ............................................................................................................... 115
6.2. Experimental Section ................................................................................................ 117
6.3. Results and Discussion .............................................................................................. 119
6.3.1. Titration Behavior of Star-Shaped PDMAEMA ....................................